Xenophage is a fighting game in the same genre as Mortal Kombat. This game features scrolling arenas that also zoom in and out, depending on how far apart the fighters are from each other. This is a unique feature in fighting games. The fighters all come from unique alien planets, so they look very cool and unusual. It's up to you to figure out their special abilities and moves.
Argo Games has generously made this shareware game freeware.